What if? (Nuclear waste)

[Chaotic Neutral]

I am wondering what would happen if the entire worlds supply of high level radioactive waste was placed in these locations:

A. Siberia

B. Sahara Desert

They are covered in concrete.

How large would the avoid death zone be from the waste? 10 mile radius? 100 mile radius?

How long could it be there before it leaks into ground water?


(n00b prepares for insults)

[Stark]

If the waste was vitrified and under a few dozen meters of concrete, why would there even BE a 'death zone'?

[Sea Skimmer]

In the desert spent fuel rods in concrete on the surface would last for thousands of years if not tens or hundreds of thousands of years depend on how much rainfall actually occurs and how abrasive the local sand is. Look at the Pyramids. Four thousand years on and most damage is from looting the sites for building material.

One of the main reasons to bury underground is not because that’s a better place to put nuclear waste, but because of fears of what happens if people find and or vandalize the waste containers in the far future. The waste makes its own heat, so it will keep its containment structure dry within a modest radius. So concrete in a really dry desert ought to basically only suffer damage from chemical weathering. Course over the span of thousands of years the climate could shift anyway, another reason why deep underground storage is favored.

[Chaotic Neutral]

So basically transportation to Russia or Africa, some landmines, some AA weapons, and water uranium removal are the only things between us and unlimited energy?

[PeZook]

So basically transportation to Russia or Africa, some landmines, some AA weapons, and water uranium removal are the only things between us and unlimited energy?

There's the teeny tiny matter of constructing trillions of dollars worth of infrastructural projects with an extremely high lead time (decades) and overcoming the immense political inertia against doing so, plus training enough people to run the plants and uranium extraction facilities plus security and transportation for both.

Easy.

[Zixinus]

You know, you can always recycle the waste (some of it can be re-used and for example, "depleted uranium" is just regular uranium) and up (or rather, lower) the half-life of non-usable radioactive material. That way, they'll radiate away into stable elements within a few months or less.

Problem is of course that it requires large expertise and facilities and political will that most politicians refuse to do anything with, due to how loaded the idea is.

[Sea Skimmer]

You know, you can always recycle the waste (some of it can be re-used and for example, "depleted uranium" is just regular uranium) and up (or rather, lower) the half-life of non-usable radioactive material. That way, they'll radiate away into stable elements within a few months or less.

Problem is of course that it requires large expertise and facilities and political will that most politicians refuse to do anything with, due to how loaded the idea is.

Well this is a thread specifically about high level waste; low level solid waste like DU wasn’t ever a very big deal. You can use it as reactor shielding in the nuclear plants themselves. Most DU mind you comes from military enrichment programs; civilian fuel has low enrichment so you don’t end up with nuclear as much surplus U-238.

Reprocessing though is a mixed blessing. While it reduces the mass of high level waste by better then 90%, it produces a huge quantity of low and mid level waste much of which is liquids. Liquids are annoying since about the only thing you can do with them is store them in massive tanks, or for really low level liquids you can evaporate them to reduce the mass. But in the end, we have no good means of final disposal. Out at the Hanford site the US has 200 something 1 million gallon tanks of liquid nuclear waste and aside from maintaining the tanks no one knows what the fuck to do with it all. This is with a budget measured in billions per year just to clean up that one place too.

So in many respects it’s just easier to keep all the spent fuel in fuel rods and dispose of those. If we ignored political realities then we would have no trouble finding spots to shove all the spent fuel the world has and will have in the future. We can always dig it back up later if we find a cleaner way of reprocessing (unlikely) or if a compelling uranium shortage forces the matter. After all it’s not like all that radioactivity wasn’t already in the ground, its just decaying faster. Of course this idea forces more uranium mining, which creates its own liquid waste trouble but that could be eliminated through sea water uranium extraction or reduced by better mining methods.

[fnord]

WHat about non-aqueous reprocessing methods, such as fluoride volatility?

[Chaotic Neutral]

I guess I figured that there was a bigger reason to not using nuclear power than "it's expensive" and "radiation is teh evilz".

[Lord of the Abyss]

I guess I figured that there was a bigger reason to not using nuclear power than "it's expensive" and "radiation is teh evilz".

No, that's pretty much it. Radioactive waste isn't something you want to spread on your breakfast cereal, but it isn't the Doom Substance antinuclear types make it out to be. And the more dangerous high level waste doesn't even stay that dangerous; it decays fast for the same reason it puts out more radiation, it's composed of elements with shorter halflives.

[Chaotic Neutral]

I figured it was a bigger problem than it is since that's pretty much the only reason not to go all-nuclear.

Oh well, my faith in humanity continues its downward spiral.

[Zaune]

One suggestion I heard was encasing it in lead-glass bricks, encasing them in concrete and disposing it in the deepest parts of the ocean. That could work pretty well as long as the containers are sufficiently resilient.

[Sky Captain]

One suggestion I heard was encasing it in lead-glass bricks, encasing them in concrete and disposing it in the deepest parts of the ocean. That could work pretty well as long as the containers are sufficiently resilient.

That would be a waste of valuable resource since most of the waste that comes out of current reactors is made up from U 238 which can still be used as nuclear fuel in breeder reactors.

[sketerpot]

Hell, the waste that comes out of most reactors in the US can be used directly as fuel in Canadian CANDU reactors. I think we should stop calling it waste and call it what it really is: slightly used fuel.

[Archaic`]

Kind of makes me wonder if the use of it as fuel could be sold to the rabid anti-nuclear environmentalist types by stealing the old motto of "reduce, reuse, recycle".

[Sky Captain]

I think it could work to gain the support for development of next generation reactors that could run on light water reactor spent fuel. Evironmentalists usually freak out about what to do with spent fuel so the solution would be to use up that fuel to full potential and generate large amounts of clean energy in the process.

[fnord]

As for the DUPIC fuel cycle (Direct Use of Pwr fuel In Candu), for typical LWR burnups, South Korean experiments indicate ~90% destruction of initial Pu, and overall ~60% destruction (since there's some Pu bred during irradiation in CANDU).

Archaic', I doubt that that will be enough to sell it to the rabid anti-nukes, who seem, to me, awful like fundamentalists when challenged re: their beliefs being a load of crap. I would be glad to be proven wrong, though.

A couple of things that would sod up use of the DUPIC cycle in the US:
1 - Not invented here
2 - I believe current CANDU designs have a slightly positive void coefficient (reactivity change due to 100% loss of coolant) of reactivity (approx 10 milli-k, but only inserted fairly slowly). As far as I understand, a reactor design must have all coefficients of reactivity negative to pass NRC muster.

This is offset by the fuel temperature coeff. of reactivity, varying between -0.004 to -0.013 milli-k/deg C, and the design of the reactor, with both a relatively cool moderator able to double up as emergency fuel coolant, and two independent automatic shutdown systems to slam the brakes on before that full 10 milli-k reactivity is inserted.

[Lord Insanity]

What we really need is Integral Fast Reactors. Interview with nuclear physicist Dr. Charles Till. Basically this is the reactor design we will be building in quantity when the anti-nuclear idiots get their heads out of their asses.